The purpose of this grant is to bring together a variety of scientific disciplines to bear on a number of specific drug abuse problems. We currently have major projects in the areas of narcotics and narcotic antagonists, marihuana, phencyclidine, the sedatives, and hypnotics and inhalants. In the area of narcotics and narcotic antagonists, we are carrying out extensive studies ranging from synthetic chemistry to behavior, to characterize their stereospecificity and mechanism of action. Our studies with marihuana involve characterization of specific binding sites and their antinauseant mechanisms against the cancer chemotherapeutic agents. In the sedative-hypnotic area, we are attempting to develop specific barbiturate antagonists. We are continuing to characterize the dependence potential of phencyclidine and are developing methods to more accurately assess the behavioral effects of abused inhalants in the rodent. Finally, we are continuing to develop new and improved methods for assessing the abuse potential of drugs.